Archive for the ‘Environment’ Category

The rig belonged to Transocean Ltm., but it was BP that submitted, and then altered, the design of the well that led to the blowout.

It was BP that chose the risky option of using only 6 centralizers on the final string of casing when their own analysis demonstrated that channels would be created in the final cementing of that casement.

It was BP that told the Schlumberger crew that a cement-bond log on that final cement job was unnecessary even though it was clear that the practice was standard operation in the completion of wells, and would have found some of the flaws inherent in the design that led to the blowout.

It was BP that chose to ignore industry standards when it chose not to fully circulate the drilling mud which would have given indication of dangerous levels of formation fluids in the mud.

It was BP that chose to not install a lock down sleeve that would have provided another redundancy against communication of formation fluids through the well head.

It seems apparent that BP chose a sub-standard design that ignored standard protocol in an attempt to save a couple of days on-site. Their attempt, if successful, would have saved only a fraction of the total cost of the well bore, and in relation to the profits that the reservoir hold, not even a mere pittance.

No one, that I am aware of, is angry at the British people, but we are furious at the criminal neglect of a company that has long flouted industry standards, and chooses profits over people… going all the way back to its days as the Anglo Iranian Oil Company.

BP has been dumping kill mud for a couple of days, now, off and on, and the well still flows. Granted, the initial dump might have been merely an attempt to understand the parameters of the system, and what it could withstand, but it appears to have been a failure. Contrary to initial reports of an admiral in Louisiana, the pill didn’t overcome the pressure of oil and gas escaping the system. BP estimated that it would take 1300 bbs of kill mud to fill the bore; they had 90,000 bbs on hand, and they stopped pumping after 16,000 bbs had been injected. Apparently, the vast majority of the mud was escaping through the riser, so they decided to re-assess(???).

When they started pumping again, they decided to go with a “junk” shot in an attempt plug some of the openings. The “junk” consists of pieces or rubber, small spheres, pieces of rope…, and whatever else might help to seal, or reduce, some of the leaks. The ideal being that the kill mud will have more area to “push” against, and hopefully, push the oil and gas down to the base of the well. If successful, the weight of the mud will effectively balance formation pressure, and then cement will be pumped to permanently seal the well.

BP has said that the process will take 36 to 48 hours before they will know if the process is successful, and that it appears that it is working, we are coming up on that time. Some engineers and geologist knowledgeable in petroleum extraction have described the process as “pissing in the wind”.

Looking at the feed from the ROV, one notices the white-snow like-material floating down. It leaves me wondering if it is gas hydrates forming from escaping hydrocarbons, if so, it doesn’t bode well for this attempt at kill the flow.

At about 09:15 this morning, something dramatic happened. Was it a “junk” shot, or was there some kind of failure. Check out the video at about 16 secs, and then at 1:14:

If this fails, they will next attempt to cut the top of the riser and install the Top Hat. It will be fitted with grommet to fit tightly over the top of riser. While, this won’t eliminate all of the oil and gas that is escaping, it should catch most of it… if all goes according to plan.

Tomorrow BP will attempt to “top kill” the well that is spewing-who knows how much-oil into the Gulf of Mexico(GOM). BP estimates somewhere around 5000 bbs/day are escaping from the collapsed riser and blowout preventer(BOP), but researchers at Purdue, using estimates from live feeds, estimate the flow somewhere between 40000-100000 bbs/day.

The Purdue results appear to be high; top producing wells in the GOM generate about 50000 bbs/day. This well’s location is in an area(Miss. Canyon Block 252) of the gulf that isn’t as productive as some other areas. So, I tend to accept BP’s estimates… within a margin of error, of course.

The “top kill” procedure involves pumping drilling mud into the BOP in pressures greater than the escaping oil and gas. The ideal is that the pressure from the pumps combined with the weight of the overlying column of mud will displace the hydrocarbons in the production string of casing from the well head to the base of the well, and then fill the casements-effectively blocking the leak. Cement will then be pumped into the string to seal the well… if all goes according to plan.

And, therein is the problem-nothing has gone according to plan. BP, and others, have speculated that the reason for the initial blow out was that a poor seal in the contact between the production casing and the protective casing at the base of the well. Apparently, the blow by was noted by engineers when mud pit volume increased out of proportion-well logs indicate that twice they stopped pumping mud in the two hours before the blow out!

In yesterday’s press briefing, BP noted that in finding cause of the blow out, the “investigation is focused on the following seven mechanisms.”

1. The cement that seals the reservoir from the well;
2. The casing system, which seals the well bore;
3. The pressure tests to confirm the well is sealed;
4. The execution of procedures to detect and control hydrocarbons in the well, including the use of the BOP;
5. The BOP Emergency Disconnect System, which can be activated by pushing a button at multiple locations on the rig;
6. The automatic closure of the BOP after its connection is lost with the rig; and
7. Features in the BOP to allow Remotely Operated Vehicles (ROV) to close the BOP and thereby seal the well at the seabed after a blow out.

Regarding 3 above: rumor has it that a well known, and very expensive geotech firm was on the platform to do cement-bond logs, and that in a hurry to get off site(so the completion crew could move in???), BP’s top guy on-site put a stop order on the c-b logs. One thing is known-the geotech firm confirmed that they pulled their people 6 hours before the blow out- which was 14 hours after the final cement job for the seal started pumping.

There are other rumors floating around that the well was “kicking”… hard, and that for that reason, a “dump kill” was recommended hours before the blow out.

I guess that we will find out in Congessional hearings.

There are a lot problems with the “top kill” plan. Some have speculated that the mud, under those pressures, will fracture the formation, and that this will lead to greater flow at the base. Fracking wells is a common procedure to increase production in reservoirs, but as the sediments in the gulf are very permeable(around 30%), and barely consolidated, it doesn’t seem that if the formation does frak, that it would a problem.

Though, a real possibility is that blockages in the string will force the mud out the BOP, eroding what constraints are inhibiting the flow. Another danger could be a blow out in the containment string near the surface… if the seals are bad, and there are blockages, the mud could force its way into the containment nearer the surface where that part of the string doesn’t generally encounter those types of pressures.

BP estimates for success are 60-70%. If unsuccessful, a “junk” shot will be attempted in which various sized rubber balls will be injected into the system; If that fails, an attempt will be made to cut off the top of the damaged BOP and affix the Lower Marine Riser Package(Top Hat) to the clean surface.

I wish the crews luck tomorrow. Hopefully, by tomorrow night the well will be sealed… but I doubt it. From the opinions of engineers and geologists, that I have read, this thing might be flowing until the relief wells are finished in the late summer.

Note: I am not a petroleum geologist, and I do not work in the industry. If I have misconstrued anything, or is there is more to add, let me know in the comments.